Drive mechanism



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l F. E. sMi'rH DRIVE MECHANISM Filed March 26, 1925 5 Sheetsheet 2 sa 55mm-e DRIVE MECHANI SM Filed March ze, 1925 sheets-sheet s Patented Fels. lilo lgl.

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Application filed March Q5,

To all viv/10m. fr m cry oo'noerrz.

Be it known that l, Fimrm lil. lurru7 e citizen et' the United itzitt and .otident ot Scottdale, in the county ot lllertnioreluud 5 und Stute of Fenn sylvonifi` have invented certain new and useful lmproveurente in Drive ll'lechanisins, of which the following is a speeitieetion.

This invention relates to drive meehzmem i@ for endless conveyors und more portie lurly to tandem drive pulleys t( endless hell; Conveyors7 and has for its olijeet the provi-- Sion oli' Such o. drive in which one o l the pulleys of the tandem dri'lfe lwill 'function :is u drive pulley only when the conveyor belt slips ou the other pulley, and which will nornmlly function zw an idler pulley.

Another object; i.; to provide such o tun dem drive with inerme lor automatically 'forming ii 'positive drive connection between :i source ot power und the pulley normally 'unetioriiug :xeon idler pulley when the belt slips on the other pulley.

Il. further object is to provide o. tandem l drive for belt conveyors having the novel urrongement, Construction :ind combination et parte hereinafter described and illustrated in tlie following drawings.

lu the drawings:

Figure 1 is o somewhat diagrmnmatio elevation ot zi. conveyor embodying my invention.

Figure 2 is en enlarged plain of the 'tarideurdrive embodying my invention.

Figure 3 le o sido elevation o1' the ratchet. coupling.

Figure 4 :i sectional elevation of the. ratchet couplitfg;

Figure 5 ieri Sectional. elevation showing;Y o modified Form of eonetruetion. A

Figure 6 is :i sectional elevation on the line vll-Vl oit Figure Referring more particularly to the drow ings, the. numeral designates the conveyor Sli belt which is,tr:uned around suitable idler pulleyl srt the end t tho conveyor. und tandem drive pulleys l and intermediate the ends olf' the conveyor. lil'hile not Shown, it `will he understood that euituhle eupport ing rollers` muy he provided ziloi'ip; tlieleugth ot the roureyer to support 4the :envoyer heit.

The tandem drive liulley 1-, 'is prefer-nhl); made of sligrl tly less; diameter than the pnl-- 1925. Serial No. 183539.

ley so when. power is applied to the pulley 5 und the heit 2 started in motion the pulley l will travel :it o grenier ll. Rill., providing tlv` heit. doer not slip., than the pulley 5.

The pulleys 1' und 5 :ire mounted on drive shafts C aud T, respectively, which ere geared together by gears 8 and it. and the g'eilr 9 it; in mesh with o pinion 10 ou a power Shaft 11 ,Connected with the :u'mziture Shaft l2 ol it Y motor 1.4;. The gears 8 and 9 are equal So that if there was no iuterrei'iing mechanism the shafts G and 7 end pulleys l and 5 would he compelled to rotate at the same speed, :uid the belt i). would he compelled to constantly slip on the pulley 1.

In the pressent construction, however, l loire dividedthe drive shaft G for 'the pulley l irmiug an idler portion (L, and fr drive portion Z), and connected said portions by a. ratchet. coupling 16.

The ratchet Coupling' 16 comprises e raitehetJ wheel member 17 lixedly mounted on the idler portion a, oit the shalt t5., and il homing,ir memher 18 uixedly mounted on the drive portion ot the Shaft und freely supporting the ond ot the portion o ol' the' shaft. The housing 18 around the ratchet f wheel 17 und has a plurality of dog;` meer here 19 pivotully mounted therein and :rdzroted to engage the teeth of the ratchet Wheel '17.

ln operation, when the motor 14 is set in motion the sluitt i" und pulley und the drive portion l), of the slm'fl. (3, will he rotated it. equal speeds, and it the holt 2 did not slip, the pulley 4 and portion o, ot the Shu't't t3, 'would he rotated at :i Slio'litly greater Speed than the pulley 5, shatt 'Z und portion l) ol the shalt t3, due to its lQmtiller difuneter. However,dne to the storting leech the holt 2 will slip 'on the pulley 5, sind the pulley will therefore tend to rotate :it a. gre-.iter speed then the pulley lli/'lien the pulley 41 und portion o? of the shz'iitt 6, tend to rotate :it u lefeer speed than the positively driven members, the ratchet Coupling' 16 Wil :i positive coupling since the (logre 19 vwill engage the teetl'ifol the ratchet. wheel 17 therefore, the pulley 4f; will lie poeitirel'j driven :it the emu ll. l?. M. :is the pulley 5. lt/flor thehlt im#` .ieon Set in motion the lip ou the pulleyi will diminish :ttul liniilly Stop, whereupon the pulley Ll und portion o of its slizrftwill. rotirte :it u. greater lt. P. lll.

ratchet ring 18? formed' integral with the housing 18". and its inner surface forms a` support for'the end of the portion L of the shaft 6. The end of the portion a, of the shaft 6, is provided with an anti-frict1on bearing 30 which fits within the ring 18k.y

A. suitable dog carrying ring 3l is mounted for free rotation on the portion a, ofthe shaft 6, and is of such size as to lit aroind the ratchet ring 18b in spaced relation. Sultable dogs 19a are carried by the rlng 31 and are adapted to engage the teeth of the vratchet ring 18".

A suitable clutch shoe formed in two semicircular is mounted within the housing 18a and`adapted to engage the inner peripheryT thereof,.to form a drive connection. pivotally mounted on the arms 34 ot a supporting yoke 35 keyed on the shaft portion a, of the shaft 6. The segments 33 are connected 'and normally tensioned toward each other in collapsed position by springs 40. l

Cam levers, ,36 are pivotally mounted on the ends of the vshoe segments as at 37, and have their cam heads 38 arranged so as to torce the segments apart and into contact with the inner periphery of the housing i6e when said levers are rocked in one direction about their pivotal mountings 37. The lower ends of the levers 36 are pivotally connected to suitable projections 39 on the ring 31.

The operation oi this clutch is substantiallythe same as the referred form with the exception that it wlll Ibe smoother in its action.

lVhen the motor lei is set in motion the shaft 7 and pulley 5 and the drive por tion Z1, of the shaft 6, will be rotated at equal speeds, and if the belt 2 did not slip, the pulley i and port-ion a, of the shaft 6, would be rotated at a slightly greater speed than the pulley 5, shaft 7 and portion F) of the shaft 6, dueto its smaller diameter. However, dueto the starting-load, the belt 2 wili slip on the pulley 5, and they pulley 5 will therefore tend to rotate at a greater speed than the pulley 4, whichv is driven by the belt 2. Wvhen the pulley l and por tion of the shaft 6, tend to rotate at a lesser speed than the positively driven mem-4 bers, t e ratchet ring 18b will engage the dogs 19 on the ring 31, thereby rotating the The shoe segments 33 are each' ring 31 so as to operate the cam levers 36 and expand the clutch shoe segments 33 into engagement with the housing 18 and form a drive connection between shaft parts a and b.

After the belt 2 has been set in motion, the slip on the ulley 5 will di minish and nally stop, wiiereupon the pul ley 4 and portion a, tate at a greater R. P. M. than the pulley 5i of its shaft 6, will roand the positive driven elements due to its the shaft 6.

The advantages of this construction will be readily appreciated by those skilled in the art. By this construction, or its equivalent, all the advantagesA of a tandem drive are obtained for starting or on extra loads, while under normal operation the advantages of a single drive pulley are obtained.

Thilo l have shown and described one specific embodiment of my invention,'it.will be understood that I do not wish 'to belim ited thereto since various modifications may` be made without departing from the scopr `of my invention as described in the ap pended claims. l

I claim: l

l. The combination ,with an endless conveyer ot' tandem drive pulleysover whic?. said conveyer is trained, one of said pulley. being of aI slightlg,r smaller diameter thai'y the other so as to norma-ll compel a fastearotation to equal the sur ace speed of th.y larger pulleyVdrive shafts for said pulleys. the drive shaft for said smaller diamete:v pulley being divided intermediate its end` forming a drive portion and an idler porv tion, a source of power having a geared connection with the drive shaft of the larger diameter pulley and the drive` portion of the drive shaft for the smaller diameter pulley so as to positively drive said larger diameter pulley and said drive portion of the smaller diameter pulley drive shaft at the same speed, and a coupling connecting the drive and idler portions of the drive shaft for said smaller diameter pulley, said I coupling being adapted to permit free rotation of said smaller diameter pulleyA and idler 'portion of said smaller diameter pnl ley drive shaft relative to said drive por tion at a greater speed thansaid drive portion of said shaft, and to automatically form a drive connection between said drive and idler portions of said shaft when lsaid positive drive,

skdriveshaft for the smaller diameter smaller diameter pulley tends to rotate at a lesser speed than said drive portion of its drive shaft.

2. The combination with an endless conveyer of tandem drive pulleys over which said conveyer is trained, drive shafts for said pulleys, the shaft for ,one of said puls leys haringn a geared connection with a source of power forming a positive drive, the other of said drive shaftsfbeing divided intermediate its ends, one portion of said second named shaft having a geared connection with a source of power forming a a coupling connecting the other portion of said second named shaft with said first named. portion, and means `n said coupling for automatically forming a positive connection between said shaft portion when said second named portion' tends to rotate at a lesser speed than said first named portion.

S. The combination with an endless conveyer of tandem drive pulleys. over which said conveyer is trained, drive shafts for said`pulleys, the shaft for one of said pulleys having a geared connection with a source of` power forming a positive drive, the other of said drive shafts being, divided intern'iediate its ends, one portion ofsaid second named shaft having;r a geared connection with a source of power forming a positive drive, and a ratchet coupling connecting the other portion of said second named shaft with said first named portion, said couplingF comprising a ratchet Wheel member secured to said second named portion of said shaft, a housing secured to said first named portion of said shaft, and dog members carried by said housing and adapted to automatically engage with said ratchet wheel and form a positive connection be'.M tween said shaft portions when said secon named portion tends to rotate at a lesser speed than said first named portion.

4. rlhc combination with an endless conveyer of tandem drive pulleys over which said conveyor is trained, one of said pulleys being of a slightly smaller diameter than the other, drive shafts for said pulleys, the drive shaft. for said smaller diameter pulley being divided intermediate its ends forming a drive portion and an idler portion, means for driving the drive shaft of the larger diameter pulley and the drive portion of the pulley at 'substantially the same speed, andmeans for automatically forming a positive drive between the drive and idler portions of the drive shaft for said smaller diameter pulley `vvhen said pulley tends to rotate at a lesser speed than said drive portion of said shaft.

5. The combination with an endless conveyer of tandem drive pulleys over which said conveyer is trained, one of said pulleys being of a slightly smaller diameter than thefother, drive shafts for said pulleys, the

- drive shaft for said smaller diameter pulley being,y divided intermediate its ends forming a drive portion and an idler portion, means for driving the drive shaft of the larger diameter pulley vand the drive portion of the drive shaft for the smaller diameter pulley at substantially the same. speed, and a coupling connecting' the drive and idler portions of the drive shaft for said smaller diameter' pulley, and means in said coupling for automatically forming a positive connection between said shaft portions when said smaller diameter pulley tends to rotate at a lesser speed than said drive portion" of its drive shaft.

6. The combination with an endless con veyer of tandem drive pulleys over which said conveyor is trained, one 'ofsaid pulleys being of' a slightly smaller diameter than the other, drive shafts for said pulleys. the drive shaft for said smaller diameter pulley being: divided intermediate its ends forming a drive portion and an idler portion, means for driving the drive shaft of the larger diameter pulley and the drive portion of the drive shaft for the smaller diameter pulley at substantially the same speed, and a ratchet couplingr connecting the drive and idler portions of the drive shaft for said smaller diameterpulley, said coupling comi prisinr,r a ratchet wheel member secured toy said idler portion-of said shaft, a housing secured to said drive portion of said shaft, and dog members mounted in said housing and adapted to automatically engage with said ratchet Wheel and form a positive drive connection between the drive and idler portions of said shaft when said smaller diameter pulley tends to rotate at a lesser' speed than the drive portion of its shaft.

In testimony whereof I have hereunto set my Ihand.

FRANK E. SMITH. 

